[Elecraft] Excessive SWR Faulting KPA500

[Bob McGraw]

Sounds as though the antenna has failed on those 3 bands.   I doubt it 
is the KPA500.   Check the KPA500 feeding a known good 50 dummy load.    
If it is good there, then it is the antenna.   If it shows the same 
results as with the antenna, then it is the amplifier.

Also you can bypass the KPA500 to STBY mode and check the system by 
observing the SWR on the K3.

73

Bob, K4TAX


On 4/17/2020 7:18 PM, k2te at juno.com wrote:
> I discovered a problem this afternoon where the KPA500 is faulting on 20,
> 17 and 12 meters.  Set up here is the K-line, K3/KAT500/KPA500.
> Everything had been working fine until this point.  I get a hard fault
> (error code 9) on the three bands which means excessive SWR even though
> it has tuned fine before switching from standby.  Antennas: 6BTV vertical
> and Inverted Vs for 17 and 12.  The Vs are fed from a common point.  The
> KPA500 works fine on 80 thru 10 on the 6BTV except 20 of course.  I tried
> turning down the power when on 20 (via the K3 drive) but the SWR runs up
> and faults.
>
> I checked the Elecraft website but no schematics for the KPA500.  My
> guess is the LPF units for the bands in question have gone TU.
>
> 73 de Ed
>
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